In a bidirectional drive tape cartridge of the type shown in U.S. Pat. No. 3,692,255 in which the tape moves at high speeds between two reels and is subjected to high accelerations when the tape direction is reversed, it is important to minimize tape tension variations at the transducer head. Otherwise tape to head contact may be lost and data compromised.
U.S Pat. Nos. 4,581,189 and 4,466,564 disclose drive belts, typically made of polyurethane, for use in such tape cartridges particularly configured to minimize tape tension variations characterized as flutter. More particularly, the disclosed drive belts are described as having a microscopically rough surface between 0.2 and 40 micrometers (8 to 1600 microinches) peak to peak to promote the release of air from between the belt and the tape for the purpose of minimizing variations in tape tension and speed.
Applicant's parent application Ser. No. 07/662,755 filed Mar. 1, 1991 describes a magnetic tape cartridge including an improved drive belt for engaging a magnetic tape to transport the tape between first and second spaced reels. The drive belt improvement is based on the recognition that variations in tape tension and speed can be minimized by minimizing the difference between the static and dynamic friction between the engaged surfaces of the tape and drive belt. More specifically, Applicant's parent application describes a drive belt having a smooth nontextured drive surface having a frictional characteristic relative to the tape surface such that the ratio of static to dynamic coefficients of friction between the surfaces is less than 2.